procfs_subr.c revision 1.36.2.4
1 /* $NetBSD: procfs_subr.c,v 1.36.2.4 2001/11/14 19:17:12 nathanw Exp $ */ 2 3 /* 4 * Copyright (c) 1994 Christopher G. Demetriou. All rights reserved. 5 * Copyright (c) 1993 Jan-Simon Pendry 6 * Copyright (c) 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Jan-Simon Pendry. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: procfs_subr.c,v 1.36.2.4 2001/11/14 19:17:12 nathanw Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/time.h> 49 #include <sys/kernel.h> 50 #include <sys/proc.h> 51 #include <sys/vnode.h> 52 #include <sys/malloc.h> 53 #include <sys/stat.h> 54 55 #include <miscfs/procfs/procfs.h> 56 57 void procfs_hashins __P((struct pfsnode *)); 58 void procfs_hashrem __P((struct pfsnode *)); 59 struct vnode *procfs_hashget __P((pid_t, pfstype, struct mount *)); 60 61 LIST_HEAD(pfs_hashhead, pfsnode) *pfs_hashtbl; 62 u_long pfs_ihash; /* size of hash table - 1 */ 63 #define PFSPIDHASH(pid) ((pid) & pfs_ihash) 64 65 struct lock pfs_hashlock; 66 struct simplelock pfs_hash_slock; 67 68 #define ISSET(t, f) ((t) & (f)) 69 70 /* 71 * allocate a pfsnode/vnode pair. the vnode is 72 * referenced, and locked. 73 * 74 * the pid, pfs_type, and mount point uniquely 75 * identify a pfsnode. the mount point is needed 76 * because someone might mount this filesystem 77 * twice. 78 * 79 * all pfsnodes are maintained on a singly-linked 80 * list. new nodes are only allocated when they cannot 81 * be found on this list. entries on the list are 82 * removed when the vfs reclaim entry is called. 83 * 84 * a single lock is kept for the entire list. this is 85 * needed because the getnewvnode() function can block 86 * waiting for a vnode to become free, in which case there 87 * may be more than one process trying to get the same 88 * vnode. this lock is only taken if we are going to 89 * call getnewvnode, since the kernel itself is single-threaded. 90 * 91 * if an entry is found on the list, then call vget() to 92 * take a reference. this is done because there may be 93 * zero references to it and so it needs to removed from 94 * the vnode free list. 95 */ 96 int 97 procfs_allocvp(mp, vpp, pid, pfs_type) 98 struct mount *mp; 99 struct vnode **vpp; 100 long pid; 101 pfstype pfs_type; 102 { 103 struct pfsnode *pfs; 104 struct vnode *vp; 105 int error; 106 107 do { 108 if ((*vpp = procfs_hashget(pid, pfs_type, mp)) != NULL) 109 return (0); 110 } while (lockmgr(&pfs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0)); 111 112 if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) { 113 *vpp = NULL; 114 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 115 return (error); 116 } 117 vp = *vpp; 118 119 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 120 vp->v_data = pfs; 121 122 pfs->pfs_pid = (pid_t) pid; 123 pfs->pfs_type = pfs_type; 124 pfs->pfs_vnode = vp; 125 pfs->pfs_flags = 0; 126 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 127 128 switch (pfs_type) { 129 case Proot: /* /proc = dr-xr-xr-x */ 130 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 131 vp->v_type = VDIR; 132 vp->v_flag = VROOT; 133 break; 134 135 case Pcurproc: /* /proc/curproc = lr-xr-xr-x */ 136 case Pself: /* /proc/self = lr-xr-xr-x */ 137 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 138 vp->v_type = VLNK; 139 break; 140 141 case Pproc: /* /proc/N = dr-xr-xr-x */ 142 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 143 vp->v_type = VDIR; 144 break; 145 146 case Pfile: /* /proc/N/file = -rw------- */ 147 case Pmem: /* /proc/N/mem = -rw------- */ 148 case Pregs: /* /proc/N/regs = -rw------- */ 149 case Pfpregs: /* /proc/N/fpregs = -rw------- */ 150 pfs->pfs_mode = S_IRUSR|S_IWUSR; 151 vp->v_type = VREG; 152 break; 153 154 case Pctl: /* /proc/N/ctl = --w------ */ 155 case Pnote: /* /proc/N/note = --w------ */ 156 case Pnotepg: /* /proc/N/notepg = --w------ */ 157 pfs->pfs_mode = S_IWUSR; 158 vp->v_type = VREG; 159 break; 160 161 case Pmap: /* /proc/N/map = -r--r--r-- */ 162 case Pmaps: /* /proc/N/maps = -r--r--r-- */ 163 case Pstatus: /* /proc/N/status = -r--r--r-- */ 164 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 165 case Pmeminfo: /* /proc/meminfo = -r--r--r-- */ 166 case Pcpuinfo: /* /proc/cpuinfo = -r--r--r-- */ 167 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 168 vp->v_type = VREG; 169 break; 170 171 default: 172 panic("procfs_allocvp"); 173 } 174 175 procfs_hashins(pfs); 176 uvm_vnp_setsize(vp, 0); 177 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 178 179 return (error); 180 } 181 182 int 183 procfs_freevp(vp) 184 struct vnode *vp; 185 { 186 struct pfsnode *pfs = VTOPFS(vp); 187 188 procfs_hashrem(pfs); 189 190 FREE(vp->v_data, M_TEMP); 191 vp->v_data = 0; 192 return (0); 193 } 194 195 int 196 procfs_rw(v) 197 void *v; 198 { 199 struct vop_read_args *ap = v; 200 struct vnode *vp = ap->a_vp; 201 struct uio *uio = ap->a_uio; 202 struct proc *curp = uio->uio_procp; 203 struct pfsnode *pfs = VTOPFS(vp); 204 struct lwp *l; 205 struct proc *p; 206 207 p = PFIND(pfs->pfs_pid); 208 if (p == 0) 209 return (EINVAL); 210 211 /* XXX NJWLWP 212 * The entire procfs interface needs work to be useful to 213 * a process with multiple LWPs. For the moment, we'll 214 * just kluge this and fail on others. 215 */ 216 217 if (p->p_nlwps > 1) 218 switch (pfs->pfs_type) { 219 case Pnote: 220 case Pnotepg: 221 case Pstatus: 222 case Pmap: 223 case Pmem: 224 case Pcmdline: 225 break; 226 case Pregs: 227 case Pfpregs: 228 case Pctl: 229 default: 230 return (EOPNOTSUPP); 231 } 232 233 l = LIST_FIRST(&p->p_lwps); 234 235 switch (pfs->pfs_type) { 236 case Pregs: 237 case Pfpregs: 238 case Pmem: 239 /* 240 * Do not allow init to be modified while in secure mode; it 241 * could be duped into changing the security level. 242 */ 243 if (uio->uio_rw == UIO_WRITE && 244 p == initproc && securelevel > -1) 245 return (EPERM); 246 break; 247 248 default: 249 break; 250 } 251 252 switch (pfs->pfs_type) { 253 case Pnote: 254 case Pnotepg: 255 return (procfs_donote(curp, p, pfs, uio)); 256 257 case Pregs: 258 return (procfs_doregs(curp, l, pfs, uio)); 259 260 case Pfpregs: 261 return (procfs_dofpregs(curp, l, pfs, uio)); 262 263 case Pctl: 264 return (procfs_doctl(curp, l, pfs, uio)); 265 266 case Pstatus: 267 return (procfs_dostatus(curp, l, pfs, uio)); 268 269 case Pmap: 270 return (procfs_domap(curp, p, pfs, uio, 0)); 271 272 case Pmaps: 273 return (procfs_domap(curp, p, pfs, uio, 1)); 274 275 case Pmem: 276 return (procfs_domem(curp, l, pfs, uio)); 277 278 case Pcmdline: 279 return (procfs_docmdline(curp, p, pfs, uio)); 280 281 case Pmeminfo: 282 return (procfs_domeminfo(curp, p, pfs, uio)); 283 case Pcpuinfo: 284 return (procfs_docpuinfo(curp, p, pfs, uio)); 285 286 default: 287 return (EOPNOTSUPP); 288 } 289 } 290 291 /* 292 * Get a string from userland into (buf). Strip a trailing 293 * nl character (to allow easy access from the shell). 294 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 295 * will automatically add a nul char at the end. 296 * 297 * Returns 0 on success or the following errors 298 * 299 * EINVAL: file offset is non-zero. 300 * EMSGSIZE: message is longer than kernel buffer 301 * EFAULT: user i/o buffer is not addressable 302 */ 303 int 304 vfs_getuserstr(uio, buf, buflenp) 305 struct uio *uio; 306 char *buf; 307 int *buflenp; 308 { 309 int xlen; 310 int error; 311 312 if (uio->uio_offset != 0) 313 return (EINVAL); 314 315 xlen = *buflenp; 316 317 /* must be able to read the whole string in one go */ 318 if (xlen < uio->uio_resid) 319 return (EMSGSIZE); 320 xlen = uio->uio_resid; 321 322 if ((error = uiomove(buf, xlen, uio)) != 0) 323 return (error); 324 325 /* allow multiple writes without seeks */ 326 uio->uio_offset = 0; 327 328 /* cleanup string and remove trailing newline */ 329 buf[xlen] = '\0'; 330 xlen = strlen(buf); 331 if (xlen > 0 && buf[xlen-1] == '\n') 332 buf[--xlen] = '\0'; 333 *buflenp = xlen; 334 335 return (0); 336 } 337 338 const vfs_namemap_t * 339 vfs_findname(nm, buf, buflen) 340 const vfs_namemap_t *nm; 341 const char *buf; 342 int buflen; 343 { 344 345 for (; nm->nm_name; nm++) 346 if (memcmp(buf, nm->nm_name, buflen+1) == 0) 347 return (nm); 348 349 return (0); 350 } 351 352 /* 353 * Initialize pfsnode hash table. 354 */ 355 void 356 procfs_hashinit() 357 { 358 lockinit(&pfs_hashlock, PINOD, "pfs_hashlock", 0, 0); 359 pfs_hashtbl = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, 360 M_WAITOK, &pfs_ihash); 361 simple_lock_init(&pfs_hash_slock); 362 } 363 364 void 365 procfs_hashreinit() 366 { 367 struct pfsnode *pp; 368 struct pfs_hashhead *oldhash, *hash; 369 u_long oldmask, mask, val; 370 int i; 371 372 hash = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, M_WAITOK, 373 &mask); 374 375 simple_lock(&pfs_hash_slock); 376 oldhash = pfs_hashtbl; 377 oldmask = pfs_ihash; 378 pfs_hashtbl = hash; 379 pfs_ihash = mask; 380 for (i = 0; i <= oldmask; i++) { 381 while ((pp = LIST_FIRST(&oldhash[i])) != NULL) { 382 LIST_REMOVE(pp, pfs_hash); 383 val = PFSPIDHASH(pp->pfs_pid); 384 LIST_INSERT_HEAD(&hash[val], pp, pfs_hash); 385 } 386 } 387 simple_unlock(&pfs_hash_slock); 388 hashdone(oldhash, M_UFSMNT); 389 } 390 391 /* 392 * Free pfsnode hash table. 393 */ 394 void 395 procfs_hashdone() 396 { 397 hashdone(pfs_hashtbl, M_UFSMNT); 398 } 399 400 struct vnode * 401 procfs_hashget(pid, type, mp) 402 pid_t pid; 403 pfstype type; 404 struct mount *mp; 405 { 406 struct pfs_hashhead *ppp; 407 struct pfsnode *pp; 408 struct vnode *vp; 409 410 loop: 411 simple_lock(&pfs_hash_slock); 412 ppp = &pfs_hashtbl[PFSPIDHASH(pid)]; 413 LIST_FOREACH(pp, ppp, pfs_hash) { 414 vp = PFSTOV(pp); 415 if (pid == pp->pfs_pid && pp->pfs_type == type && 416 vp->v_mount == mp) { 417 simple_lock(&vp->v_interlock); 418 simple_unlock(&pfs_hash_slock); 419 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) 420 goto loop; 421 return (vp); 422 } 423 } 424 simple_unlock(&pfs_hash_slock); 425 return (NULL); 426 } 427 428 /* 429 * Insert the pfsnode into the hash table and lock it. 430 */ 431 void 432 procfs_hashins(pp) 433 struct pfsnode *pp; 434 { 435 struct pfs_hashhead *ppp; 436 437 /* lock the pfsnode, then put it on the appropriate hash list */ 438 lockmgr(&pp->pfs_vnode->v_lock, LK_EXCLUSIVE, (struct simplelock *)0); 439 440 simple_lock(&pfs_hash_slock); 441 ppp = &pfs_hashtbl[PFSPIDHASH(pp->pfs_pid)]; 442 LIST_INSERT_HEAD(ppp, pp, pfs_hash); 443 simple_unlock(&pfs_hash_slock); 444 } 445 446 /* 447 * Remove the pfsnode from the hash table. 448 */ 449 void 450 procfs_hashrem(pp) 451 struct pfsnode *pp; 452 { 453 simple_lock(&pfs_hash_slock); 454 LIST_REMOVE(pp, pfs_hash); 455 simple_unlock(&pfs_hash_slock); 456 } 457 458 void 459 procfs_revoke_vnodes(p, arg) 460 struct proc *p; 461 void *arg; 462 { 463 struct pfsnode *pfs, *pnext; 464 struct vnode *vp; 465 struct mount *mp = (struct mount *)arg; 466 struct pfs_hashhead *ppp; 467 468 if (!(p->p_flag & P_SUGID)) 469 return; 470 471 ppp = &pfs_hashtbl[PFSPIDHASH(p->p_pid)]; 472 for (pfs = LIST_FIRST(ppp); pfs; pfs = pnext) { 473 vp = PFSTOV(pfs); 474 pnext = LIST_NEXT(pfs, pfs_hash); 475 if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid && 476 vp->v_mount == mp) 477 VOP_REVOKE(vp, REVOKEALL); 478 } 479 } 480
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